First off all, thank you for giving us the opportunity to toss out our ideas
for the satellite!
Since the power budget of the cubesat will be very limited, I feel an FM
repeater is the way to go. Nihon University's SEEDS II cubesat shows that it
is possible to run an FM transmitter for at least a significant time within
the power budget of a single unit cubesat, and its signal is very easily
received even with simple handheld 435MHz beams. At the same time SO-50,
with its 250mW transmitter, shows that such a small transmitter power can
still be reliably and clearly received.
The FM transmitter involved in this design could be used for other purposes
as well. It could be used for SSTV transmissions, AFSK telemetry, or even a
digitalker. So if the satelite also has scientific payloads, the same
transmitter could first be used to downlink payload data, and then could be
switched to repeater mode when the experiments are complete. A BPSK
transmitter could also be used but this would limit the audience - there are
many hams out there, like me, who don't own all mode VHF/UHF gear.
73,
Sam KC2LRC - FN13